Air pollution reduction system

ABSTRACT

An air pollution reduction system embodying dielectric means to induce electrostatic forces in the path of a polluted fluid stream to cause precipitation of solids in said stream.

United States Patent 11 1 Shriner 1 June 5, 1973 1541 AIR POLLUTIONREDUCTION SYSTEM 3,330,284 7/1967 Seman et al. ..131/107 x 3,394,7077/1968 Ellis ,.131/264 X, [76] lnvemor' ge i' f ifi' z g g 3,492,9982/1970 Mascaro ..131/261 R x IIVC, prmg l6 3,545,179 12/1970 Nelson etal... ..55/457 X 22 Filed; Oct 6, 1971 3,563,004 2/1971 Schouw....55/103 1,632,325 6/1927 Andersn.. ..55/466 1 1 pp 136,857 2,758,6668/1956 Prentiss ..55/103 x FOREIGN PATENTS OR APPLICATIONS [52] U.S. Cl...55/103, 55/124, 55/136,

55/146, 55/155, 55/485, 55/516, 55 527, 680,297 /1952 Great Britain..55/457 55 0 275 0 311 131 792,068 3/1958 Great Britain..... ....55/l03[51] Int. Cl ..B03c 15/30 1041528 5/1924 Swllzerland 55/485 [58] Fieldof Search ..55/103, 131, 132,

55/155, 136 37 138 2 29 485 45 Primary ExaminerDenn1s E. Talbert, Jr.523, DIG. 30, 124, 146, 516, 527; 131/261 AtwrneyElmer Zwickel R, 264,10.7, 262 R, 262 A, 262 B; 60/275,

311 [57] ABSTRACT An air pollution reduction system embodying dielec-[561 References Cited tric means to induce electrostatic forces in thepath of UNITED STATES PATENTS a polluted fluid stream to causeprecipitation of solids in said stream. 2,918,139 12/1959 Silverman........55/457 X 3,307,332 3/1967 Grace et al. ..55/103 11 Claims, 9Drawing Figures AIR POLLUTION REDUCTION SYSTEM The invention relates toan air pollution reduction system and is more particularly concernedwith such a system wherein the removal of particulate and chemicalpollutant contents of the fluid stream is obtained by precipitation ofsuch matter through activation of an electrostatically charged fieldgenerated from a surface having dielectric properties disposed in thepath of said stream.

As disclosed in my U.S. Pat. No. 3,587,210, issued June 28, 1971, it iscommon practice to separate and collect solid and liquid contaminatingparticles suspended in moving hot or cold gases by producing anelectrical field within a chamber thorugh which said gases are moved. Itappears that the very fine colloid particles which are entrained in theexhaust gases emitted from an internal combustion engine are especiallyconductive to the formation of smog conditions. Accordingly, coalescenceof said entrained colloids are fine particulate material, so as tofacilitate the entrapment thereof before discharge to the atmosphere, isof great significance in reducing smog producing conditions. To thisend, the present invention incorporates novel means whereby thecolloidally suspended pollutant particles of the pollutant-carryingfluid stream pass through a space containing air vanes capable ofgenerating an electrostatic force which, when pplied to the particles inthe fluid stream, cause said particles to be precipitated from saidstream and collected in a collection chamber.

It is accordingly an object of this invention to provide a new andimproved means for controlling and reducing the contaminant content ofapollutant carrying fluid stream.

Another object is to provide a self contained air pollution reductiondevice for ready association with the exhaust system of an internalcombustion engine or the like.

Another object of the invention is to provide a system for the treatmentof a pollutant carrying fluid stream wherein a tubular unit in the pathof said stream is provided with vanes constructed of or coated with adielectric material susceptible to activation by the heat generated inan automobile exhaust system to establish and maintain anelectrostatically charged surface on said vanes.

Another object is to provide a series of like tubular units joined instacked relation end to end in alignment with the path of a pullutantcarrying fluid stream wherein each of said units is provided with aseries of circumferentially spaced vanes or air foils constructed of orcoated with dielectric material effective to establish and maintainelectrostatically charged fields effective to coalesce particulatematter in said fluid stream.

Another object is to provide a system which is applicable not only tothe exhaust train of an internal combustion engine, but is also adaptedfor use in other installations such as smoke stacks, air conditioners,and similar sources of pollutant-carrying fluid streams.

Another object is to provide a device of the character referred to withnovelly formed vanes or airflows.

Another object resides in the provision of a system which is relativelyinexpensive to manufacture and in; stall and which requires a minimum ofcare and maintenance.

Other objects and advantages of the invention will become apparent withreference to the following description and accompanying drawings.

In the drawings:

FIG. I is a view of an exemplary exhaust system of an internalcombustion engine having installed therein the anti-pollution device ofthe present invention.

FIG. 2 is an enlarged longitudinal sectional view of the device.

FIG. 3 is an end elevational view of the device.

FIG. 4 is a view similar to FIG. 3, showing a modified structure. I

FIG. 5 is a detail of the vane in the FIG. 3 disclosure.

FIGS. 6 through 9 are views similar to FIG. 5, showing modified forms ofvanes or air-flows.

As shown in FIG. 1 of the drawings, an air pollution reduction device 11incorporating the features of this invention is shown as occupying aposition in the tail pipe 12 of a typical internal combustion engineexhaust system including a muffler 13 to which the tail pipe 12 isjoined in upstreamward relation to the device 11. Accordingly, whenexhaust gases reach the device 11, much of the heat and pulse wave ofsuch gases have been absorbed during passage through the muffler 13,which allows for miniaturizing the overall size of the device 1 l ascompared with one that would be required under conditions where thegases entered the device 1 l at close to sonic velocities and maximumtemperatures, with consequent loss in the operating efficiency of thedevice 11.

As shown, the device 11 comprises a cylindrical body 14 open at bothends. The body may be made of one piece but, as shown, preferably iscomprised of a series of like units 14a which are nested togetherend-to-end so as to enable one to provide a device of any desired lengthdepending upon its specific installation. Each unit is fabricatedpreferably from plastic, ceramics or even paper. The material used willbe determined by the ultimate use to which the device is to be put. Inthe instance of muffler application, the material would preferably beceramic or perhaps high heat resistant plastic so as to resist the heatof the gases; whereas, if the units are for use in filtering cold gasessuch as in an air conditioner, they may be fabricated from low heatresistant plastic or paper suitably treated as hereinafter noted.

In either event, the circular wall of each unit has in; tergral with ita plurality of radially arranged vanes 15 which may be suitably shapedas shown in FIGS. 3 or 4. In the FIG. 3 illustration the vanes 15 areformed with a thickened medial portion 15a and taper toward both ends.These may be termed positive vanes whereas, when shaped as shown at 16in FIG. 4 (negative vanes) they are thinner in their medial portions16a. It has been established by experiment that the positive" type shapeis more efficient than the negative type shape. The axial center of theunit may have an axial core such as shown at 17 in FIG. 3, or it may beleft open as shown in FIG. 4.

When hot gases pass through the device when fabricated from ceramics,glazed or unglazed, and either coated with a thin layer of Teflon or notcoated; or from a high temperature plastic, there is an electrostaticforce generated on the vanes during the passage of exhaust gases throughthe device. This electrostatic force is effective to cause precipitationof the pollutants (solids) which are collected within collectionchambers 18 containing shreaded or fibrous material 19, such asaluminum, spun glass, etc. Otherwise stated, the products of combustionpass through areas of voltage change and coalesce according to theircollodial properties. As a result, the gases leaving the discharge endof the device are substantially free of pollutants.

In the present invention a series of like tubular units 14a of suitablesize and shape are joined to form a rigid stacked assembly along a lineextending lengthwise of the line of travel of the fluid stream which isassociated with it. When thus joined in a rigid stacked assembly, theunits are arranged in the exhaust pipe 12 in downstreamward relation tothe muffler 13, so as to occupy a position in relation to the mufflercorresponding to that illustrated in FIG. 1. In the instance of aplastic unit, each unit 114 is preferably molded of hightemperature-resistance synthetic resinous composition such as phenolicresins or acrylic polymers. In either event the front end of each unitMa is of reduced transverse diameter so as to provide an inwardly offsetneck 11a about which the open rear end of each unit 14a rearwardlythereof has an external telescopic fit. The units 14a are secured inrigid stacked assembly by a cemented joint between each neck 1 la andthe portion of the adjacent unit enclosing said neck, or by othersuitable connecting means. Thus, the exposed outer walls of each unitforms a smooth continuation of the corresponding wall of the otherattached units. The number of such units 14a may be varied to suit therequirements of the installation to which the system is to be applied.In the event that the units are fabricated from porous material, such asceramics, it is advisable to provide a layer of electric insulationmaterial between the unit and the tail pipe.

Should paper be used to fabricate the units 14a, it is preferable thatit be of a thickness of about 0.005 to 0.008 inch and that it be coatedwith shellac in ethanol; polyethylene in methyle ketone or a mixture ofvarnish, linseed oil and a thinner, as these substances have anelectrostatic force generating potential.

It is to be observed that as an incident to the flow of a heated gaseousstream, in a path obstructed by the vanes 15 of each unit 11, the heatof such stream acting on the dielectric surface of the vanes ofair-flows causes an electrostatically charged field or layer to begenerated thereon. Under these conditions the particles of contaminantmaterial in the fluid stream encountering said electrostaticallyconditioned field become charged so as to coalesce the collodialparticles and render the same susceptible to entrapment of theparticles. Preferably, the vanes are formed with reduced trailing edgesas shown in FIGS. 6 through 9 to reduce sonic velocity.

As the fluid stream thus moves from unit 14a to unit 14a rearwardlythereof, the collodial effluent remaining in the fluid streamdischarging from one unit onto another unit will undergo further actionof the succeeding unit with the result that the fine particule size atthe out-put end of the most downstream positioned unit 14a will producea very substantial agglomeration of the particles in relation to thecondition of such particles atthe most upstream positioned unit 14a.Thus, when a quantity of collodial particles are collected in thecollection chambers of each unit, said unit can be discarded and a newunit placed in the system. 1 While the electrostatic charged field ineach of the units 14a is maintained in a hot gas exhaust system of anautomobile internal combustion engine on the basis of the heat effectsof such eshaust system applied to the vanes of each of said units, it isto be understood that such units are equally efficient in connectionwith installations, as for example, in the confines of a smoke stack. Insuch installations, facilities providing a source of initiation of theelectrostatic field, such as auxiliary heating devices, could occupy aposition at a suitable distance upsteam of the area occupied by thepollutant reduction unit 11 forming the subject of this invention.

A unit made of wood, for low heat application, functions veryefficiently when the surfaces of the vanes are coated with shellac. Whenceramics are used, should it be glazed, it may not be necessary to coatit with any dielectric material. However, it will be appreciated that byutilizing a relatively thin layer or coating of suitable syntheticresinous material such as Teflon (polytetrofluoroethylene) or otherplastic material such as polystyrene, on the unglazed surface of atleast the' vanes 15-16, relatively high resistive surface conditionscapable of easy activation in the generation of an electrostatic fieldmay be obtained while using a relatively cheap and less resistivematerial such as ceramics for construction of the unit including thevanes. The use of such a coating thus provides a unit which is moreeconomical to produce, without sacrificing the efficiency of the unit inthe activation of the required elctrostatic field.

It has been found that the condensate collected in the unit isrelatively dry having the appearance of a charred rock-like masscomprised of small gravel sized modules rather than as a tar as so oftenoccures in devices of this general character. The collection of theprecipitate as pellets is far supperior to collection of fluids which,in a muffler installation, drip from the tailpipe onto the pavement.

Although I have described preferred embodiments of my invention inconsiderable detail, it will be understood that the description thereofisintended to be illustrative, rather thasn restrictive, as details ofthe structure may be modified or changed without departing from thespirit or scope of the invention. Accordingly, I do not desire to berestricted to the exact construction described.

I claim:

1. An air pollution reduction device for placement in the path of apollutant-laden stream of gases comprising, in combination, a tubularbody open at both ends, a plurality of stationary vanes radiallyarranged in the interior of said body, said vanes extendinglongitudinally of the body, and a coating of polytetrafluorethylene onthe vane surfaces so as to be (present surfaces) capable of inducingelectrostatic charges in the stream of gases flowing thereover.

2. The device recited in claim 1, in which the body is comprised of aseries of units each containing vanes and which are nested together endto end.

,3. The device recited in claim 2, in which each unit includes acollection chamber.

4. The device recited in claim 3, in which there is a mass of fibrousmaterial in each collection chamber.

5. The device recited in claim 1, in which the vanes are uniformilyspaced apart circumferentially.

6. An air pollution reduction device for placement in the path of apollutant loaded stream of gases comprising, in combination, a tubularbody comprised of a series of like units nested end to end and having anopen gas inlet end and an open gas outlet end, a first series ofstationary vanes disposed within said tubular body adjacent the inletend, a collection chamber downstream from said vanes, a second series ofstationary vanes disposed within said body in axial alignment with thefirst series of vanes, a second collection chamber downstream of saidsecond series of vanes, a third series of stationary vanes in saidtubular body in axial alignment with the second series, a thirdcollection chamber downstream of said third series of vanes, the vanesin each series being uniformily spaced apart circumferentially and eachhaving a surface of dielctric material, and a mass of fibrous materialin each collection chamber, said vanes functioning to generateelectrostatic charges in the gases passing thereover resultmg inprecipitation of pollutants which pollutants are collected in saidchambers to remove said pollutants from the gases prior to passage tothe outer atmosphere through the outlet end.

7. The device recited in claim 6, wherein the dielectric material iscomprised of polytetrafluoroethylene.

8. The device recited in claim 6, in which at least the vanes are'formed of ceramic material.

9. The device recited in claim 6, in which at least the vanes are formedof paper coated with a dielectric mateial.

10. The device recited in claim 6, in which the vanes have an ovoidconfiguration.

11. The device recited in claim 6, in which the vanes have an air-foilconfiguration.

2. The device recited in claim 1, in which the body is comprised of aseries of units each containing vanes and which are nested together endto end.
 3. The device recited in claim 2, in which each unit includes acollection chamber.
 4. The device recited in claim 3, in which there isa mass of fibrous material in each collection chamber.
 5. The devicerecited in claim 1, in which the vanes are uniformily spaced apartcircumferentially.
 6. An air pollution reduction device for placement inthe path of a pollutant loaded stream of gases comprising, incombination, a tubular body comprised of a series of like units nestedend to end and having an open gas inlet end and an open gas outlet end,a first series of stationary vanes disposed within said tubular bodyadjacent the inlet end, a collection chamber downstream from said vanes,a second series of stationary vanes disposed within said body in axialalignment with the first series of vanes, a second collection chamberdownstream of said second series of vanes, a third series of stationaryvanes in said tubular body in axial alignment with the second series, athird collection chamber downstream of said third series of vanes, thevanes in each series being uniformily spaced apart circumferentially andeach having a surface of dielctric material, and a mass of fibrousmaterial in each collection chamber, said vanes functioning to generateelectrostatic charges in the gases passing thereover resulting inprecipitation of pollutants which pollutants are collected in saidchambers to remove said pollutants from the gases prior to passage tothe outer atmosphere through the outlet end.
 7. The device recited inclaim 6, wherein the dieLectric material is comprised ofpolytetrafluoroethylene.
 8. The device recited in claim 6, in which atleast the vanes are formed of ceramic material.
 9. The device recited inclaim 6, in which at least the vanes are formed of paper coated with adielectric mateial.
 10. The device recited in claim 6, in which thevanes have an ovoid configuration.
 11. The device recited in claim 6, inwhich the vanes have an air-foil configuration.